Heat exchanger, especially a heat exchanging module, for a motor vehicle

ABSTRACT

The invention relates to a heat exchanger for a motor vehicle. Said heat exchanger especially comprises a heat exchanging module provided with a plurality of pipes and corrugated ribs which are interconnected in the form of a network structure, and two lateral parts ( 1 ) which border the heat exchanging module on opposite sides. At least one break-off point ( 8 ) is provided on a lateral part ( 1 ).

The invention relates to a heat exchanger, in particular a heatexchanger module, for a motor vehicle, according to the preamble ofclaim 1.

In heat exchangers in the form of a heat exchanger module, that is tosay in which the condenser and the coolant cooler are connected to oneanother as a unit via corrugated ribs and side parts, temperaturechanges and associated periodically different temperature levels in theheat exchanger and coolant cooler result, due to the different thermalexpansion states, in stresses which may lead to leaks. Furthermore, thetemperature changes and the associated stress changes load the formedtube ends of the flat tubes of the heat exchanger module, and this maylead, here too to leaks.

For this reason, in conventional heat exchangers, expansion beads in theside part are provided, as illustrated, for example, in FIG. 3 in theregion identified by a circle. The production of expansion beads of thistype requires special forming tools and an additional consumption ofmaterial as a result of the shaped-out beads.

The object of the invention is to improve a heat exchanger of this type.

This object is achieved by means of a heat exchanger having the featuresof claim 1.

According to the invention, a heat exchanger for a motor vehicle with aheat exchanger module is provided, which has a side part with at leastone predetermined breaking point. In this case, the predeterminedbreaking point lies preferably in the region of the tube forming or atan interface between the condenser part (in particular, flat-tubecondenser) and the coolant cooling part (in particular, coolant cooler)of the heat exchanger module.

Preferably, the predetermined breaking point is formed by webs, inparticular by three webs, which are separated from one another by meansof cutouts arranged in a V-shaped manner.

Preferably, the webs have a width of 0.5 to 2 mm, in particular 1 to 1.5mm, with the result that the predetermined breaking point breaks evenunder relatively low loads and the flat tubes of the heat exchanger areprotected.

Preferably, the heat exchanger is designed in such a way that a marginalregion of the side part is bent through approximately 90° along thelongitudinal edge of the side part and is interrupted in the region ofthe predetermined breaking point by cutouts.

Preferably, the webs are delimited laterally by cutouts, at least one ofwhich is of angular design in the direction of the webs, in particularwith an angle of 90° or less, that is to say is sharp-edged.

The invention is explained in detail below by means of an exemplaryembodiment, with reference to the drawing in which:

FIG. 1 shows a perspective illustration of a side part of a heatexchanger module;

FIG. 2 shows a top view of an end region of the side part of FIG. 1;and.

FIG. 3 shows a perspective illustration of a side part of a heatexchange module according to the prior art.

A heat exchanger according to the invention, in the form of a solderedall-aluminum heat exchanger module, has a flat-tube condenser, a coolantcooler, which comprise a plurality of flat tubes and corrugated ribsconnected to one another in the manner of a net structure, and two sideparts 1 which are located opposite one another and one of which isillustrated in FIGS. 1 and 2.

Reference is made below to FIG. 2, the configuration of the side parts 1being essentially symmetrical at both ends. The side part 1, a bentsheet aluminum part, has a marginal region 2 running essentially aroundthe entire side part 1 and bent to approximately 90° upward, that is tosay away from the flat-tube condenser and coolant cooler. The marginalregion 2 is interrupted, in an end region 3 of the side part 1, by twocutouts 4 which are arranged on the two longitudinal sides of the sidepart 1 and which have two edges 5 and 5′. In this case, the edgearranged further away from the end region 3 is designated by 5 and theedge lying nearer to the end region 3 is designated by 5′. In each case,formed approximately symmetrically, a cutout 6 running inward obliquelyto the longitudinal axis of the side part 1 is provided, spaced apartsomewhat from the edge 5, so that the two cutouts 6 are arranged in aV-shaped manner. The end region 3 and the middle region of the side part1 are connected to one another by means of three webs 7. The webs 7 havea width of approximately 1.5 to 2 mm and form a predetermined breakingpoint 8. In this case, the cutouts 4 and 6 are arranged in such a waythat in each case at least one sharp-edged corner region of the cutouts4 and 6 delimits a web 7, so that a high notch effect is achieved and,as a result, the predetermined breaking point 8 breaks even underrelatively low stresses. This occurs particularly in the event of atemperature change, as a result of which the coolant flat tubes expandin the direction of the block height, that is to say in the longitudinaldirection of the side part, and said stress thereby arises on the sidepart and leads to a predetermined break, with the result that thecoolant flat tubes are relieved of load. In this case, the side part ishighly stable in the direction of the block width, so that thepredetermined breaking point has no influence on the tensioning(cassetting) of the heat exchanger module.

LIST OF REFERENCE SYMBOLS

1 Side part

2 Marginal region

3 End region

4 Cutout

5, 5′ Edge

6 Cutout

7 Web

8 Predetermined breaking point

1. A heat exchanger for a motor vehicle, in particular with a heatexchanger module, which has a plurality of tubes and corrugated ribsconnected to one another in the manner of a net structure, and with twoside parts (1) which frame the heat exchanger module on opposite sides,characterized in that at least one predetermined breaking point (8) isprovided on one side part (1).
 2. The heat exchanger as claimed in claim1, characterized in that the predetermined breaking point (8) isarranged in the region of the tube forming or at an interface betweenthe condenser part and the coolant cooling part of the heat exchangermodule.
 3. The heat exchanger as claimed in claim 1, characterized inthat the predetermined breaking point (8) is formed by webs (7).
 4. Theheat exchanger as claimed in claim 1, characterized in that thepredetermined breaking point (8) is of V-shaped design.
 5. The heatexchanger as claimed in claim 4, characterized in that the webs (7) arearranged at the three corners of the V-shaped predetermined breakingpoint (8).
 6. The heat exchanger as claimed in claim 5, characterized inthat the webs (7) have a width of 0.5 to 2 mm, in particular 1 to 1.5mm.
 7. The heat exchanger as claimed in claim 1, characterized in that amarginal region (2) of the side part (1) is bent through approximately90° along the longitudinal edge of the side part (1) and is interruptedin the region of the predetermined breaking point (8) by cutouts (4). 8.The heat exchanger as claimed in claim 3, characterized in that webs (7)are delimited laterally by cutouts (4, 6), at least one of which is ofangular design in the direction of the webs (7).
 9. The heat exchangeras claimed in claim 8, characterized in that the cutouts (4, 6) have atleast one edge (5) which has an angle of 90° or less.